The series primarily focuses on the daily lives of Victorian police officers working at a police station in the fictional small town of Mount Thomas.
S12:E01 - Mind Wide Open
A woman claims to be a victim of alien abduction. Then she says her neighbour has been abducted too and he confirms it. When senior constable says she has as well and a little boy goes missing, what is going on? P.J. does not believe it for one minute.
S12:E01b - Reasonable Doubt
The Heelers must deal with a child killer (Chris' nephew) who has been found not guilty by a jury. When he returns to Mt. Thomas and gets involved in a fight with a group of angry locals, Jonesy arrests him and clearly plans to mete out his own form of justice, in spite of opposition from his colleagues. With the mob out for blood, the acquitted man is sheltered at the station as an armed standoff errupts at the Imperial.
S12:E02 - On the Inside
Evan and Susie investigate a women's prison where they suspect not everything is run by the book.
S12:E03 - Secrets and Lies
Jo is determined to reopen a case which leads to old wounds and new ones, for two families over their missing sons.
S12:E04 - Yesterday's Hero
A footballer returns home and tries to make a fresh start but is turned down and has many people against him. Susie has a date with him and this clashes with her relationship with Jonesy, over and over again. Who is committing the burglaries and what about the evidence the police find?
S12:E05 - The Cull
A meeting about culling kangaroos takes place after Susie and Jonesy come across carnage of a lot of animals slaughtered with a high powered assault rifle, leaving the area like a battlefield. This will bring two men against each other who served in the same platoon in the Vietnam war and both men have secrets to hide, that will lead the outspoken Jonesy, to do something drastic before he truly understands something of the situation.
S12:E06 - Life of the Party: Part 1
There a drug problem again and Joney's brother is in town chasing it up. The police seem to have leads but explosions and evidence adds further proof. But Jonesy and his brother are at serious odds over this and with Joney's big 30th birthday coming up, the big guns are called out.
S12:E07 - Life of the Party: Part 2
The Jones family are reeling from the shock of what has happened. Susie tries to help, whilst there is still the matter of the drugs issue to deal with and blame is shifting once again and this will enrage Jonesy even more. The real culprits will be found but the police will have a job making one of them get justice they deserve.
S12:E08 - Keeping Mum
A man shot dead and an 11 year-old boy stealing from a car shop, have something in common. Jo tries to do a good turn and it will raise a whole lot of questions about parenting. Things will not be as simple as it seems and it will be hard on Jo and P.J.
S12:E09 - Payback
Whilst on patrol, Susie discharges her firearm and shoots Ben. Inspector Falcon-Price and ESD are called in to investigate and further investigations are not going well to prove that it was an accident, as the past history between Susie and Ben over Brad is looked into.
S12:E10 - Echoes
Jo and P.J. take the plunge, but its a case of a teacher and his female students that Maggie never got to deal with, has P.J. thinking about Maggie when awake and when asleep. This makes Jo question their recent decision and case of the teacher and his female students will make P.J. say what he truly believes.
S12:E11 - End of Innocence
Old ladies are being bashed and Clancy's detective work is very helpful. Clancy is then a target and then Tom and Jo are threatened. When incidents occur, a local criminal family are blamed and Grace just can't see the problem the same way Tom does. And threats by more people to 'get the police' are coming thick and fast.
S12:E12 - Headless Chooks
In the aftermath of the bomb explosion that destroyed the station, everyone is coming to grips with the lost lives and the new people stepping in. Nick Shultz turns up as part of the investigating team from the city. Tom is distressed that Grace is missing, and no-one can find her; he's sure the Baxters had something to do with her disappearance, but PJ suspects someone else.
S12:E13 - A Time for Mourning
Old coppers are investigating assaults on women, leaving the new coppers to deal with an old man who believes he has been robbed and someone may be after him. The rest of the police are trying to get the new offices in order, and there is a lot of anger around.
S12:E14 - Pigs Will Fly
There's no rest as a suspected bomb is found at the new police station. Tom lays down his orders. As the investigation seems to get closer and provide answers and the new recruits have to deal with a worrying break-in. And there are more deaths to come.
S12:E15 - Life Goes On
As it seems Tom has lost it in his search to find the bomber, P.J. enlists Susan's help and there is more destructive acts of violence to come. A young girl goes into labour in the public restrooms, so Susie and Jonesy have to act fast.
S12:E16 - Checkmate
Tom gets a lead but P.J. is not so sure he can trust him anymore. Tom is after the Baxters and his outlook on 'everything' seems to have changed.
S12:E17 - Don't Call Me Baby
The probationary constables have an accident and Jonesy gets involved with a woman who ex is chasing her wanting his things back.
S12:E18 - Bring It On
Joss suspects something is wrong at a golf club and has a bet with Kelly over work. Tom and Jonesy have heated words over Jonesy's relationship with Donna and her story is full of holes, but is there any truth to it?
S12:E19 - Pillow Talk
Donna is forthcoming with information but Jonesy has to get help so he asks Amy. Red herrings occur and Inspector Falcon-Price turns up wanting answers. Meanwhile a tape goes missing that's crucial for a case. Ben and Susie have to talk about their relationship.
S12:E20 - Out of Love
Jonesy is still protecting Donna, even though she is behaving oddly and doing things she should be arrested for. Chris has two unexpected visitors and the police station gets two missing animals they have to look after, till the owner turns up to collect them. Tom shows the new darker side of his character even more.
S12:E21 - Turf War
With dead bodies piling up, who is responsible and now there seems to be a dirty cop at St Davids. This is going to bring Inspector Falcon-Price and the new no nonsense Tom, to have it out on more than occasion, made all the worse with missing guns and three police officers who are in mortal danger.
S12:E22 - Away Games
Susie and Joss attend a party for a visiting Tasmanian footy team where a noise complaint has been laid, and find a girl who says she has been pack-raped. Investigations reveal that Tom's step-son Daniel was at the party, and the evidence links him to the crime. Meanwhile, a woman is feeling threatened - is it the creepy guy along the way, or her jealous ex-husband? Events push Ben to the limit, and he makes a life-altering decision.
S12:E23 - Special Treatment
As Daniel is a suspect, Tom treats him like anyone else who is suspected. The investigation into the assault continues and Inspector Draper is called in as well. Tom's new attitude will also have personal repercussions.
S12:E24 - Too Late to Say Sorry
Joss and Kelly help a woman who seems to have just given birth but things are not quite as they seem as Joss investigates further. Sergeant Holland joins the team in Mount Thomas and will make his mark.
S12:E25 - One of the Boys
There is trouble at the school with one boy apparently assaulting a girl but it's not as simple as that. This will involve the whole family and the 12 year-old is having a difficult time with one parent opposing each other. Sergeant Holland is making things difficult for Kelly and even when she makes a decision, it seems to be too late. Joss gets friendly with the mother of a woman who has been knocked off her bicycle.
S12:E26 - A Helping Hand
A man who needs a nurse has a painting go missing. Joss gets assaulted by Fay's ex-husband and this may lead to the missing painting. Joss is told to break it off with Fay, whilst Tom appears to be doing P.J. and Amy's detective work for them.
S12:E27 - Tit for Tat
Tarni Baxter is back and has a not-so-pleasant boyfriend with her. Tom makes it his mission to warn them. Sergeant Holland decides on action of his own, which increases the tit for tat action between Tom and Tarni. Kelly gets her own back on sergeant Holland and what he has been up to all comes out. Tom finally finds out the truth but his words with Roy Holland doesn't go according to plan, and puts him in a very awkward position.
S12:E28 - Crash Site
The Boss's rental car is discovered crashed and burned out on the road to Melbourne, with a charred body inside.